Fields of research

Computational neurosciences / neural theory

Research Theme

Sensory systems transduce fluctuations in the physical world into patterns of action potentials which are integrated to control motor outputs. Locomotion relies on genetically determined circuits constituted by spinal interneurons and capable of generating oscillations. Local sensory information about the outside world or the internal state seem to alter thesemotor patterns by triggering, stopping or steering locomotion. Although the advent of modern physiology shed some light on the connections of sensory cells and interneurons, most studies were limited to paralyzed preparations where local sensory inputs could not be active. So how are local mechano-, chemo-, and thermo-sensory inputs dynamically recruited in moving animals? And how are they integrated by assemblies of interneurons during locomotion? To elucidate these questions, I propose to study dynamic sensory-motor integration in spinal circuits of the tractable genetic model organism, zebrafish. The transparency of the larva enables to measure and manipulate sensory inputs with light in moving animals. In previous work, we developed in vivo optogenetic approaches for probing spinal circuits.

We identified a new proprioceptive pathway interfacing the spinal circuits with the cerebrospinal fluid (CSF). We demonstrated that remote activation of this pathway could trigger slow locomotion. We will now combine optogenetics, population imaging, physiology and quantitative analysis of behaviour in order to elucidate this novel proprioceptive function at the molecular level (Aim 1). We will extend our approach to other sensory pathways in order to unravel when sensory inputs are recruited and how they dynamically shape motor output in moving animals (Aim 2). Aim 3 will unravel how sensory inputs project and select motor patterns at the circuit level. Our studies should solve a fundamental question in neuroscience: how do spinal circuits integrate chemo- and mechano- and thermo-sensory information to produce complex motor patterns.﻿